Coarticulation: The origin of coarticulation

The concept of coarticulation, i.e. the apparent variation of segments due to the influence of adjacent or nearby segments, is central to almost any area in phonetic research. The following text considers the 'origin' of this concept from three different perspectives. In the first section the reasons why coarticulation exists in speech are outlined and the phenomenon and its underlying assumptions are presented in more detail. The second part of the paper deals with the history of the concept. Firstly, an overview of the origin of coarticulation is given from a historical point of view. Secondly, the adoption of the concept of coarticulation as the basis of a major research paradigm in speech production is discussed. The latter includes a summary of the main models and experimental results presented since the late 1960s. In the third section, finally, the ontogenetic origin, i.e. the way in which children acquire coarticulatory behaviour, is considered. 1. WHAT IS COARTICULATION, AND WHY DOES IT EXIST? The title of this chapter is deliberately ambiguous. 'Origin' refers both to the history of the scientific concept of coarticulation, and to the question of what causes the phenomena in speech which are known as coarticulation. The history of the concept will be dealt with in Section 2, while the reasons why there are phenomena in speech which we can characterize as coarticulation are dealt with explicitly below, as well as implicitly in the discussion of the history of coarticulation in Section 2. There is even a third sense of 'origin' which is dealt with briefly in Section 3, namely the way in which coarticulation develops as a child learns to speak. Coarticulation, very broadly, refers to the fact that a phonological segment is not realized identically in all environments, but often apparently varies to become more like an adjacent or nearby segment. The English phoneme /k/, for instance, will be articulated further forward on the palate before a front vowel ([ki ] key) and further back before a back vowel ([k_ ] caw); and will have a lip position influenced by the following vowel (in particular, with some rounding before the rounded vowel in [k _ ] caw). As here, some instances of coart iculat ion are available to impressionistic observation, and constitute an important part of what has traditionally been thought of as allophonic variation. In many other instances, however, the kind of